Some of you that may have had a battery replaced recently may notice that I’ve reduced the labor from 1.5 hours to 1 hour. That change just reflects that I’ve gained a lot of practice, and also accounts for the fact that I’m using a lift now rather than making house-calls and using only ramps for the service. So I apologize to anyone that recently had a battery replaced that paid for the greater labor hours.
Everything is subject to change (and other legal stuff you commonly hear…)
This is happening, people! (Or at least it’s being planned, people!)
I’m not really 100% done with this business plan and it’s begging for plenty of improvements, but the basics are there. I’ve decided that I have more to benefit by releasing it sooner, collecting feedback, and continuing to make improvements than by hiding it away until I feel that it’s perfect.
Some information may be pertinent to all Think owners– not just the ones who might need me to replace an MLEC here in Portland. But I’m not going to give away any spoilers– if you want to know what I’m talking about you’ll just have to wade through the whole thing (or let someone else in the group post it).
If you do read it, please send me an email note (firstname.lastname@example.org) with any constructive thoughts. Or if you can’t think of anything constructive, supportive is also welcome.
Business Plan, revised 2 December 2016
I was recently informed (Wednesday, October 5, 2016) that my arrangement with Green Drop Garage was not working out. Green Drop had agreed to host me as an independent contractor in their shop to work on Thinks, and they would have the benefit of labor and parts mark-ups. I did not want to be a full-time tenant, renting out a bay, because there’s not enough Think work to keep me employed full-time.
I was given 2 options: pay rent as a full time tenant at the shop or move someplace else.
Then for some strange reason they rescinded the invitation to for me to rent.
It was May of 2015 when I took these scope snapshots. If I’m remembering correctly, here’s what all the channels are probing:
Blue: The voltage at the blower, I think. I suspect that I turned the blower control to the second position which is why you see a little hump in the curve.
Red: The heater request signal, just like Carl described, going from 10% duty cycle (to request no heat) to 60% duty cycle to request heat.
Green: The run signal– probably from the key switch circuit.
Gold: An amp clamp around one of the high voltage wires to the PTC heater.
In this first image you can see that the car is running during the entire event. I happen to turn the blower on co-incidentally at the start of a heater-request pulse, and on the next pulse it has changed to 60% duty cycle. It’s about 1.5 seconds until the PTC heater actually starts drawing current, and because of its PTC nature, the element starts off cold– drawing a lot of current– and then warms up and draws less current.
In the snapshot below, I turn the key off while the heater is still running. You can interpret the green signal going to 0 V as the instant when the key is turned off. The voltage at the blower tapers down, and the heat-request signal goes away very shortly after key off. But the heater continues to draw current until the contactors open under load, and then the heater discharges the capacitor in the PCU.
The time from key off to the contactors opening is that awkward 1.5 seconds of silence when you wonder why you haven’t heard that familiar clicking that normally happens almost instantaneously when you turn the key off. There’s no way to tell how long the heater might go on drawing current if the contactors didn’t open. It definitely continues to try to draw current until after the contactors have had a chance to close again. It’s also hard to say if the CDCM was sending the heat-request signal at 1000x its present frequency if that would stop the heater from drawing current after key off. So is it a problem in the CDCM? Maybe. Is it a problem in the PTC heater control circuitry? Maybe– or at least you would think that you ought to be able to fix this problem by modifying the PTC heater.
Here’s the PTC retrofit instructions in case you’re interested:
Brake fluid. Water gets into brake fluid in just about every automobile because glycol ether is hygroscopic. Hygroscopic was a brand-new word to me when I attended automotive classes and its etymology is not clear, but it simply means that it absorbs water out of the atmosphere. (I would have expected a word like hydrophilic, but no. And glycol ether is not the only type of brake fluid, but it is by far the most common.)
Here’s the gist: I’m recommending putting a plastic bag over your brake master cylinder/reservoir to prevent water from sitting on tip of it. Continue reading Speaking of water getting where it’s not supposed to be…
A customer informed me a few days ago that a Think has a starring role in the Netflix original series Lilyhammer. Steve Van Zandt, of E-Street Band fame, stars as a mobster who moves to Norway for witness protection. He’s not thrilled with his new car, but even if it’s smaller than he’s accustomed to, he seems to make it look pretty roomy– and with enough space in the back for a sheep.
The screen shots above are stolen from Netflix– I hope they don’t mind.
One inspection I perform on a 12,000 mile service is a check of the level and condition of transaxle fluid. Most often the lubricant appears unremarkable, but occasionally I find the oil is milky, opaque and overfull. In conventional cars this usually means that coolant has contaminated the oil, which can leak happen to engine oil through a head gasket leak or to transmission fluid through a transmission cooler. Continue reading Water in the transaxle and more!
Based on an observation by Tom Goesch of ThinkParts4U and a Think owner, we’ve made a preliminary correlation between charger (or charger fuse) failure (internal to the PCU) and failure of the radiator fan low speed resistor. This is still a very new discovery, and I’m still thinking about the best course of action (and collecting better ideas from smarter people), but it’s in everyone’s best interest to get this issue checked out because the repair bill will exceed $1000 if you are so unfortunate as to be affected by it. Continue reading Radiator Fan Low Speed Resistor Failure
These are a few snapshots from a Briefing Book dated March 2011, just over 5 years ago.
I recently sent out a help request for diagnosing a car that intermittently dies while driving. I’ve attached two files of the CAN data covering two occurrences of the car spontaneously shutting down. If anyone can find the key to why the car shuts down, I’ll buy you lunch!
Here are some charts of Data2: The first one is all of the data and the second one is zoomed in to just the area surrounding the BUS HEAVY error.
I simply sorted the message IDs and assigned them integer values. Here’s a key:
(They’re not exactly in order because the spreadsheet got a little bit confused by the hexidecimal numbers, thinking they were text.)